Four members of Lebanon’s militant Hezbollah movement are being tried in absentia for the car bomb that killed Hariri and 21 others on Beirut’s downtown waterfront nearly 9 years ago.

Though efforts have been made to find the accused — Salim Jamil Ayyash, Mustafa Amine Badreddine, Hussein Hassan Oneissi and Assad Hassan Sabra — all four remain at large. If found guilty, the men could face life in prison.

At the beginning of the session, which saw Hariri’s son, former Prime Minister Saad Hariri and other family members of other victims present, Judge David Re said all necessary steps had been taken to bring the men to court.

The prosecution started their case with powerful footage of the blast that nearly tipped Lebanon back into civil war. Prosecutors say the attack was an act of terror meant to spread fear through the country.

“The attackers killed innocent bystanders: a student, a hotel worker, a cousin, a father, a brother, a daughter, friends,” said prosecutor Norman Farrell on Thursday, according to a Reuters report.

The bombing was the deadliest in a series of attacks against critics of Syria’s military dominance in Lebanon at the time. Hariri was part of the March 14 anti-Syrian opposition that was fighting a plan to extend the tenure of then-president Emile Lahoud, a close Syrian ally.

Damascus denied any knowledge of the attack. Hezbollah also denied involvement, claiming that the United States and Israel were behind the bombing. The United Nations launched the Special Tribunal for Lebanon in 2009 to probe the attack.